1. Field of the Invention
The present invention relates to a duplex printer for printing on both the front and back sides of a traveling web such as paper or textiles.
2. Description of the Background Art
As duplex printers, a printer as shown in Japanese Patent Application Laid-open No. 8-216467 (1996) is well known.
This printer includes a transport path for transporting a web with the front side up; a reversing unit for reversing a web; and another transport path for transporting a reversed web with the back side up. The printer further includes a printing unit for printing on the front side of a web; and another printing unit for printing on the back side of a web, which is provided separately from the former one.
However, the duplex printer disclosed in Japanese Patent Application Laid-open No. 8-216467 has no control mechanism that allows individual position adjustments between a web and each of the front- and back-side printing units. Thus, if a traveling web moves in zigzag only on either the front- or back-side transport path, it may be difficult to ensure registration accuracy between images printed on the front and back sides of the web.